A network engineer observes a spike in controller CPU overhead and overall network utilization after enabling multicast on a controller with 500 APs.
What feature is necessary to correct the issue?
A. controller IGMP snooping
B. unicast AP Multicast Mode
C. broadcast forwarding
D. multicast AP Multicast Mode
D
We recommend that you do not use Broadcast-Unicast or Multicast-Unicast mode on Cisco WLC setup where there are more than 50 APs connected together
Correct answer: D
Unicast mode—In this mode, the controller unicasts every multicast packet to every access point associated to the controller. This mode is inefficient but might be required on networks that do not support multicasting.
Multicast mode—In this mode, the controller sends multicast packets to a CAPWAP multicast group. This method reduces overhead on the controller processor and shifts the work of packet replication to your network, which is much more efficient than the unicast method.
https://www.cisco.com/c/en/us/td/docs/wireless/controller/7-4/configuration/guides/consolidated/b_cg74_CONSOLIDATED/b_cg74_CONSOLIDATED_chapter_01011.html